This invention relates to a bomblet having a casing of essentially rotational symmetrical cross section and a targeting device which includes a reflector (antenna) articulated to the casing. During a rotary motion of the bomblet, in response to an applied force, the reflector swings from a space-saving position of rest in the casing into a working position in which the reflector is locked. The reflector has an effective surface which, in the working position, is oriented towards the target zone and which projects beyond the cross section of the bomblet casing. A bomblet of this type is disclosed, for example, in German Offenlegungsschrift (non-examined published application) No. 3,428,051.
Bomblets equipped with an on-board targeting device are preferably used from the air against armored ground targets. Generally, for the transport over the target zone, a plurality of bomblets is accommodated within a container, for example, a rocket or the carrier casing of an artillery shell and is ejectable therefrom above the target zone at a predeterminable altitude. The bomblets then drop individually while rotating about their respective central longitudinal axis and cooperate with a mechanism which reduces their falling speed and rate of rotation.
A short period after the bomblet leaves the transport container such as a rocket or the casing of an artillery shell, the on-board targeting device of the bomblet is activated in such a manner that as the bomblet approaches the target, a signal characterizing the target may be received thereby.
In the above-noted German Offenlegungsschrift No. 3,428,051 various mechanisms are described for deploying (unfolding) an antenna of a targeting device from the inside of the bomblet casing into a working position externally thereof and to immobilize the antenna in such a deployed position.
It is a common characteristic of the described mechanisms that for initiating and carrying out the deployment of the antenna, they need an additional energy source contained in the bomblet. Thus, by igniting a pyrotechnical charge or by releasing a highly pressurized gas, a desired gas pressure is set in a gas pressure actuated plunger which operates a piston system. The resulting motion of a piston rod is converted by various mechanical means into a deploying (unfolding) motion of the antenna.
In one of the embodiments described in the Offenlegungsschrift No. 3,428,051 the immobilization of the antenna deployed into its working position depends from the terminal position of the piston rod. According to another embodiment, the deployed antenna is held in its working position by a spring loaded pin.
It has been found that in a bomblet in accordance with German Offenlegungsschrift No. 3,428,051 the positioning of the antenna is not reproducible in a satisfactory manner. First, the additionally needed energy source for deploying the antenna poses problems such as the unavoidable risks of a malfunctioning in the ignition or possible irregularities in the burning behavior of the propellant. Second, during the fall of the bomblet, a resetting force, derived from the air resistance acts on the deployed antenna; such a resetting force has to be compensated for by a counterforce in the locking support.
Such a counterforce is generated according to one embodiment described in the Offenlegungsschrift No. 3,428,051 by the pressure force of the propellant gases, acting on the piston. This means that an accurate immobilization of the antenna may be assured only if the pressure of the propellant gases can be held constant. This, however, is not possible in practice.
Another type of immobilization of the antenna described in another embodiment, involving a spring-loaded locking pin is also wrought with problems because in case of a long-term storage of the bomblet a weakening of the armed spring of the locking pin may occur.